1. Field of the Invention
The present invention relates to a terminal metal fitting.
2. Description of the Related Art
Conventionally, terminal metal fittings formed into a predetermined shape by punching a metal plate, prepared as a base material, into a predetermined developed shape and performing a bending process and the like on the plate have been known. For example, in such a terminal metal fitting, a box shape is formed when a plurality of portions of a certain part in its developed shape are bent in the same direction. The box body is then used as a terminal connecting body that is electrically connected to a counterpart terminal (refer to, for example, Japanese Patent Application Laid-open No. 2004-31034, Japanese Patent Application Laid-open No. 2005-5109, and Japanese Patent Application Laid-open No. 2003-86281).
Springback occurs in such a terminal connecting body that is obtained by performing the bending process. The springback is a tendency to return to the developed shape. For this reason, for example, in the terminal metal fittings disclosed in Japanese Patent Application Laid-open No. 2004-31034, Japanese Patent Application Laid-open No. 2005-5109, and Japanese Patent Application Laid-open No. 2003-86281, a piece part (a regulated projection unit or a holding piece) is provided on one end side of the terminal connecting body, and a groove (a regulating groove or a holding groove) into which the piece part is fitted is formed on the other end side of the terminal connecting body. In this manner, the terminal connecting body is prevented from deforming outwardly because of the springback. In a coating crimping part of the terminal metal fitting, the thickness of the barrel piece is made thinner than the thickness of the bottom part, or the thickness of the bottom part is made thinner than the thickness of the barrel piece. This is done to reduce the orthogonal sectional shape (shape of a section orthogonal to the axis line direction of an electric wire) after the electric wire is crimped to the coating portion (such as Japanese Utility Model Application Laid-open No. 6-80263 and Japanese Patent Application Laid-open No. 2013-232333).
The conventional terminal metal fitting adopts a structure in which the piece part is fitted into the groove, so as to prevent the terminal connecting body from deforming outwardly because of the springback. However, because the terminal metal fitting adopts the fitting structure, a gap between the piece part and the groove is very small. Thus, it is difficult to correctly fit the piece part into the groove, during the bending process of the terminal connecting body.